When you reached Epic or above.. You no longer can use any hero you want. Team composition is really important in this.

If you want to use certain hero which is you expert in it, it also apply for the enemy as well.

In GM division or below, both of team can use same heroes. Let say you want to use Gwen, and maybe the enemy can use Gwen as well.

But in Epic-above, your team & enemy team can't use same hero, that's why draft pick existed.

When you reached high division, the game will be more competitive. And for some people, certain heroes are threatening, in this current meta, Gwen considered as one of op heroes, let say you want to use it in ranked and she's free ban, but the enemy pick Gwen first, it's same, right? You can't pick her either. But the enemy team gets more advantage when getting her.

So that's why there's a thing like "pick & counter-pick" in draft.

But when you got no hero to counter op heroes that you can't counter. To prevent that heroes is to ban them from earlier. If you can't pick the hero that you want, so don't let the enemy pick it. That's the purpose.

Adding the banning system add more depth into the game.
1. It makes players to be more strategical coming into every match.
2. It also 'force' players to play many different hero instead of spamming 1 hero *fake cough* fanny nerds *cough*.
3. It also make the game to be more competitive.
Many other e-sport games follow this route of banning system..not just MOBA.

Someone said about creating another rank mode without the ban..haha..that is just called classic.

Well..whether the hero is op or not is not my point.
The point of banning system is to make a more strategical plays starting from the draft all the way into the match. It certainly add more depth in terms of competitive play. That is why drafting only appears in rank mode where players compete seriously for title/mmr/ranking/etc.

The banning system is not meant for players to ban certain op hero. If you watch high level pro players, the hero that you mentioned rarely get ban.
To clarify, heroes that are op or unbalanced is up to the players perspective. That is why the players should controlled which hero to ban

"What’s the point in having heroes when they get banned pretty much all the time.

Blame Moonton for not nerfing those heroes yet or not enough

"What’s the story behind banning?"

These hero is obviously op or inbalance and if enemy or team picked them they will have a good chance to win as long as they know what they're doing plus with others good team composotion and of course it will get them banned lol